For the education community amongst us, this site I recently found seems to be quite good. It's about page tells us:
Curriki is more than your average website; we're a community of educators, learners and committed education experts who are working together to create quality materials that will benefit teachers and students around the world.
Curriki is an online environment created to support the development and free distribution of world-class educational materials to anyone who needs them. Our name is a play on the combination of 'curriculum' and 'wiki' which is the technology we're using to make education universally accessible.
Curriki is built on the XWiki platform, an open source development platform and "Next Generation Wiki" application developed in Java and released the LGPL open source license.
Curriki is a non-profit 501(c)(3) corporation.
Go explore
Curriki here
